Here are some other things to consider when evaluating an information source:
Consider your information need when evaluating potential sources. Are you writing a research paper, or an opinion piece for the school paper?
What are the characteristics of the information that you are evaluating? Is it factual or analytical? Subjective or objective? Primary, secondary, or tertiary? The type of information that you need will depend on your project.
If you are using a web site, look for clues in the URL. Addresses ending with .edu, .gov, or .org are usuallly more reputable than addresses ending with .com or .net.
Be aware that bias can exist in any information source, including books owned by the library. Human understanding of events changes over time, and attitudes do as well.
When evaluating the quality of an information source, remember to use the C.R.A.P. method:
Purpose / Point of View
Here are some questions to ask yourself for each category:
Currency - How current is the information? Is the age of the publication likely to affect the conclusions drawn by the author?
Reliability - Does this work present you with high quality information? Is your topic treated as the main subject, or is it peripheral? Does the information support or disprove your thesis? Is the resource useful to your research need?
Authority - Who is the author of the work, and what are his/her credentials? Who published the work - a scholarly press, a commercial publisher, or is it self-published? If it is an online resource, can you determine who the author is?
Purpose/Point of View - What is the purpose of the resource? Is it to inform, entertain, etc? Is the purpose clearly outlined in the foreword or introduction? Is the work's audience an expert in the field or a layperson?